1. Field
One or more embodiments disclosed herein relate to a method and apparatus for performing analysis filtering or synthesis filtering using a quadrature mirror filter (QMF) bank.
2. Description of the Related Art
A digital audio coding method is a very important factor not only in the field of mobile devices but also in the field of home audio systems. Among audio coding algorithms according to ISO MPEG audio standards, MPEG layer-3 (MP3) may be used for broadcasting and multimedia contents. AAC, HE-AAC v1, and HE-AAC v2, for example, are improvements of MP3 which provide high quality music at a relatively less bit rate. According to an MPEG surrounding coding method that provides multichannel, consumers may experience not only high quality sound but also live and vivid multichannel sound. Recently, HE-AAC that is included in Dolby Pulse and MS10 is widely being used as a home audio coding method. The above-described sound coding methods all use QMF-based sub-band coding technique. Since a human's hearing system recognizes sound based on a frequency of an audio signal, the QMF-based sub-band coding technique is very effective in compression of audio and sound signals. However, the QMF-based sub-band coding requires a burden of a considerable amount of calculation to achieve its effectiveness.